Removable disk cartridges for storing digital electronic information typically comprise an outer casing or shell that houses a rotatable recording medium, or disk, upon which electronic information can be stored. The cartridge shell often comprises upper and lower halves that are joined together to house the disk. The disk is mounted on a hub that rotates freely within the cartridge. When the cartridge is inserted into platform within a disk drive, a spindle motor in the drive engages with the disk hub in order to rotate the disk within the cartridge. The outer shell of the cartridge typically has some form of opening near its forward edge to provide the recording heads of the drive with access to the recording surfaces of the disk. A shutter or door mechanism is often provided to cover the opening when the cartridge is not in use to prevent dust or other contaminants from entering the cartridge and settling on the recording surface of the disk.
Disk drives for receiving removable disk cartridges, including conventional 3.5" floppy disk drives, must have some mechanism for bringing the hub of a disk cartridge into engagement with the spindle motor of the disk drive and for maintaining tight tolerances between the cartridge hub, spindle motor and magnetic head actuator of the disk drive. In many conventional floppy disk drives, a floppy disk cartridge is guided vertically into engagement with the spindle motor of the drive which is rigidly mounted to a base plate in the disk drive. The head actuator is also mounted to the base plate. With this arrangement, it is difficult to ensure critical tolerances and spacing between the disk cartridge, the head actuator and the spindle motor.
Data storage devices, e.g. disk drives, for receiving removable disk cartridges perform a number of functions incident to the recording and/or retrieval of information from a disk cartridge. For example, critical functions include: (I) latching or holding the cartridge in place on a platform during operation, releasing and ejecting the cartridge only at an appropriate time and only under certain conditions, (ii) locking the read/write heads of the disk drive in place to prevent movement of the heads under inappropriate circumstances, and (iii) holding the platform in an unloaded (e.g., forward) position when a cartridge is not in the drive.
A conventional platform forward latch holds the platform forward when a cartridge is not in the drive. This is achieved by using an angled feature on the platform forward latch and a matching angled feature on the pin of the platform. However, under drop shock loads, tangential forces can cause the conventional latch to release and allow the platform to move back into a latch-back position, which is undesirable. In some cases, the latch-back position will allow the recording heads to move out from their parked position, thereby exposing them to head damage.
Although the art of disk drives is well developed, there remain some problems inherent in this technology, particularly preventing the platform from moving under force or shock. Therefore, a need exists for a disk drive latch member that overcomes the drawbacks of the prior art.